BIG PHYSICS, BIG QUESTIONS –

Joseph Hooker: The travelling man who became Emperor of Botany

Putting his passion on the scientific map took Joseph Hooker on wild adventures – everywhere from the Antarctic to Everest, a London exhibition shows

Hooker visited places no botanist had been before

RGB Kew

By Stephanie Pain

On the last day of September 1839, the 22-year-old Joseph Dalton Hooker boarded HMS Erebus bound for far southern seas. He spent the next four years as assistant ship’s surgeon – a lowly position but one that kick-started a career that saw Hooker become one of the greatest scientists of the 19th century.

Hooker wasn’t interested in a career in medicine or the Royal Navy. His ambition was to be a great botanist, but, as a man of limited means, he was willing to do any job that would take him to places no botanist had been before.

As part of the soon-to-be-famous Ross expedition to Antarctica, Hooker reached a record-breaking 78° south. It is, he wrote to his father, “a great consolation to me after so long a cruize to gather plants further South than have heretofore been detected”.

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For Hooker, travel (at someone else’s expense) was a means to an end. It was the way to establish his reputation as a botanist and earn a place among the well-heeled gentlemen of the scientific establishment.

Travel also provided a way to enhance the status of botany, generally dismissed as little more than collecting and classifying plants. Hooker aimed to discover universal laws that explained the distribution of plants round the world, putting botany on a par with the other great sciences.

But he also found that travel suited him. Despite hardship and danger, he liked nothing better than journeying to remote places: India and the Himalayas, Syria and Lebanon, and finally, at the grand old age of 60, America’s Rocky mountains.

Kew success

An exhibition at the Royal Botanic Gardens at Kew in London to celebrate the bicentenary of Hooker’s birth tells the story of a man who achieved what he set out to achieve and how he did it. Hooker went on to become director of Kew Gardens and president of the Royal Society.

He amassed thousands of specimens, published wonderful books and was Charles Darwin’s closest friend and supporter. He ruled over a vast global network of collectors and correspondents, and earned himself the nickname The Emperor of Botany.

Where this exhibition excels is in showing us the man behind the facts, through letters home, tiny notebooks filled with Hooker’s miniature handwriting, the weird and wonderful objects he collected on his travels, and his sketches and paintings.

Hooker’s rhododendron finds sparked a Victorian craze

RGB Kew

Seeing Hooker’s artefacts is a remarkably vivid experience. A chunk of foremast reminds us of the dangers he faced – this is a souvenir of his lucky escape when HMS Erebus and HMS Terror collided trying to avoid an iceberg in Antarctic seas.

As a one-time seagoing biologist myself, seeing Hooker’s travelling microscope reminded me how hard it sometimes is to do even basic science at sea. “When the motion of the ship is such that my things have to be lashed to the table & I have to balance myself to examine anything under the microscope I fear many errors have crept in,” he wrote in a letter home.

But Hooker’s life and soul are best revealed by the drawings and paintings at the heart of this exhibition. All Victorian botanists had to be able to draw well, capturing every feature of a living plant before it was pressed, dried and consigned to a herbarium.

Some of the finest images are of rhododendrons he discovered in the Himalayas – finds that helped trigger the Victorian craze for these showy shrubs. But although the botanical drawings and the lithographs produced from them for later publication are beautiful and instructive, the rougher sketches leave a bigger impression.

High art

There is his tent high in the Himalayas “made of a blanket thrown over the limb of a tree”, the people he met on his travels and the puppy he acquired that grew into an unexpectedly large dog. And then there’s the view from “Choonjerma pass” in Nepal, drawn in 1848.

Until recently, the significance of this sketch from Kew’s archives had gone unrecognised. The view, Hooker noted, includes “the most lofty group of mountains in Nepal”. He couldn’t tell how high they were, but “judging from the quantity of snow they must be prodigious”.

They were indeed: one of the lofty peaks was later recognised as the world’s highest mountain. This sketch is the earliest Western image of Mount Everest.

Hooker was also a mean map-maker, skilled in surveying and cartography. Maps were vital for recording where plants grew – a key requisite in his search for universal laws governing plant distribution. As he solicited ever more specimens and data from his network of collectors, he demanded the same degree of precision – not always successfully.

In his Handbook of the New Zealand Flora, he grumbled that he was “often perplexed by the collectors sending as localities the names of insignificant hamlets or streams which are not found on attainable maps”.

This exhibition is not only a timely reminder of one of the greatest natural scientists, but also a thing of beauty. I have to confess that there was something else that particularly caught my eye: a long account of expenditure from Hooker’s travels in Sikkim, north-east India.

In the not-so-distant past, New Scientist correspondents returning from assignments to far-flung places vied to submit receipts in languages and scripts they hoped no one would understand. Hooker, however, takes the prize. His account is not only written in Lepcha, it’s one of the oldest surviving examples of Lepcha writing and includes words and phrases previously unknown.